Attribute 'c++_compatible'

The pragma causes the VTable generated by the PLC compiler to be binary compatible with that of a C++ compiler. This makes it possible to access the interface methods implemented in the PLC from a TcCom module implemented in C++.

Syntax: {attribute 'c++_compatible'}

Insertion location:

The pragma must be added in the following places:

Line above the interface declaration
Line above the declaration of the individual interface methods
Line above the declaration of the function block that implements the interface
Line above the declaration of the methods that are implemented from the interface

Sample:

Declaration of a function block that implements a C++-compatible interface:

{attribute 'c++_compatible'}
FUNCTION_BLOCK FB_Sample IMPLEMENTS I_Sample
VAR_INPUT
END_VAR
VAR_OUTPUT
END_VAR
VAR
END_VAR

Declaration of a method that is defined in the interface:

{attribute 'c++_compatible'}
{attribute 'minimal_input_size' := '4'}
{attribute 'pack_mode' := '4'}
METHOD Method1 : HRESULT
VAR_INPUT
    nParameter1 : INT; 
END_VAR

See also: